The present invention pertains to a comparator macroscope or microscope for the simultaneous observation and optional photographic imaging of objects to be compared, comprising a comparator bridge for the bilateral attachment of individual macroscopes or microscopes, respectively, or of macro- or micro-objectives, a binocular tube mounted on the comparator bridge and having a beam splitter prism, a phototube arranged on the binocular tube and a marking device producing a luminous spot on the objects.
Comparator macroscopes of this type and comparator microscopes of a similar design are used, for example, in criminology, as well as in biology, medicine and industry, for comparative examinations of two different objects and also together with suitable instrumental equipment to photograph these objects. During alignment of the objects, it is often highly time-consuming to arrange the location of interest in the center of the field of vision. This is especially true when highly magnifying lenses are used, and in the examination of documents. When lenses with different parfocalizing lengths are mounted on a revolving turret, refocussing by means of the adjustment of the comparator bridge is always necessary in case of a lens change. Since there are no outwardly recognizable indications of the direction wherein the refocussing is to take place, the process is often laborious.
A multiple microscope is known from U.S. Pat. No. 3,734,593, wherein two or more observers may simultaneously observe an object by means of suitably coupled stereomicroscopes. In this device, a luminous spot is produced on the object with the aid of a fixedly installed illuminating device, and this luminous spot serves to mark the location on the object viewed simultaneously by the observers. The indicating device is adjustably vertically, whereby the size of the luminous spot may be varied. If during the viewing of the object the two fields of vision of the microscopes do not coincide, the luminous spot does not appear in the center of the field of vision of each microscope. This indicates the fact that the microscopes are focussed at different locations of the object. It is not possible with this known apparatus to examine simultaneously two different objects which are to be compared with each other, and it is immaterial in this case, since merely the degree of coincidence of the position of a certain location on the object is to be determined and no comparison is intended. Furthermore, in this apparatus, in addition to the observation light paths, a separate light path must be provided for the generation of the luminous spot, at a corresponding additional cost.
Another stereomicroscope is known from DE-AS No. 24 23 136, wherein a luminous spot is produced on the object by means of an additional focussing beam. The luminous spot is reproduced by the stereo system in intermediate imaging planes, superposed on the observation light path and then separated from the latter. Any axial displacement of the object plane defined by the luminous spot is converted by photoreceivers into a direction-dependent signal, which serves to control a focussing motor. In this manner, it is achieved that the plane of sharpness of the objectives always coincides with the object. This automatic focussing device is suited only for stereomicroscopes because of the two principal beams situated at a certain angle of convergence with respect to each other. A simultaneous observation of two objects to be compared with each other is not possible with this apparatus, which is also expensive in its design.